I use ConvertKit for my email management. I've tried quite a few - Mailerlite, Mailchimp, Flodesk and GetResponse off the top of my head, but I keep going back to ConvertKit - because it simply WORKS!
I've had clients ask me how to "segment" their list with ConvertKit - and of course there are many ways, but let me talk you through the way I do it - because I'm a HUGE fan of keeping shit simple... and I really don't see it being much more simple than this!
If you're a service-based entrepreneur then this system will work for you too - because it drops the fluff, BS and drama and just deals with the essential SEGMENTS of your list!
Now ConvertKit differs from other autoresponders in that ALL subscribers are kept in one big list - rather than a bit here, a bit there, and a bit a waaaaaay over there which you're supposed to remember to add when you write a newsletter.
But, each subscriber can be assigned to a segment (the main chunking) and can have multiple tags (behaviour related).
So for me, whether someone joins my list from downloading a freebie (I have several) - or whether they straight out buy (yep, it happens from a cold audience too, don't let anyone tell you it doesn't!) - they're tagged and segmented right away.
SEGMENTS
- NON-BUYERS (self-explanatory!)
- BUYERS (when someone buys something from me)
- SUPER-BUYERS (repeat customers)
See? Super-simple.
There's no need to have a dozen segments (categories), because you're just going to confuse yourself - and likely never use them anyway!
I'm not a fan of complicating my email autoresponder or funnels. But what these segments allow me to do is to e.g., offer a discount to my BUYERS to turn them into SUPER-BUYERS - and my SUPER-BUYERS will get extra special offers from me. I don't need to worry about "Sue from Dallas who scored Foxy Writer on the SALES QUIZ" - simply whether Sue is in my circle or not.
TAGS
On to tags. These are a little more complicated. I have a "legacy" tag which I've applied to people who've moved email system with me but never bought (still segmented to NON-BUYERS!), but I also tag which programs people buy, which SALES SUPER-POWER my subscribers have or which freebie they opted in to and in total I have about 15-20 tags although I prune these monthly because it annoys me when there's a long list of tags which are no longer relevant! 
The power of tags means that I can then apply these tags to an email sequence pertaining to what they've bought or what they've downloaded, but it doesn't affect any further behaviour within the system.
ConvertKit is waaaaaay more powerful than what I use it for - but frankly life is too short and I want to keep things simple because... I want my LIFE and my BUSINESS to be SIMPLE. That's the way I WANT it!
*ConvertKit contains an affiliate link, If you click on it and go on to buy, I may receive a small commission. Keep a gal in coffee! 
